From: Herbert Xu Date: Wed, 9 Jan 2008 11:51:59 +0000 (-0800) Subject: [ATM]: Check IP header validity in mpc_send_packet X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=1c9b7aa1eb40ab708ef3242f74b9a61487623168;p=openwrt%2Fstaging%2Fblogic.git [ATM]: Check IP header validity in mpc_send_packet Al went through the ip_fast_csum callers and found this piece of code that did not validate the IP header. While root crashing the machine by sending bogus packets through raw or AF_PACKET sockets isn't that serious, it is still nice to react gracefully. This patch ensures that the skb has enough data for an IP header and that the header length field is valid. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- diff --git a/net/atm/mpc.c b/net/atm/mpc.c index 2086396de177..9c7f712fc7e9 100644 --- a/net/atm/mpc.c +++ b/net/atm/mpc.c @@ -542,6 +542,13 @@ static int mpc_send_packet(struct sk_buff *skb, struct net_device *dev) if (eth->h_proto != htons(ETH_P_IP)) goto non_ip; /* Multi-Protocol Over ATM :-) */ + /* Weed out funny packets (e.g., AF_PACKET or raw). */ + if (skb->len < ETH_HLEN + sizeof(struct iphdr)) + goto non_ip; + skb_set_network_header(skb, ETH_HLEN); + if (skb->len < ETH_HLEN + ip_hdr(skb)->ihl * 4 || ip_hdr(skb)->ihl < 5) + goto non_ip; + while (i < mpc->number_of_mps_macs) { if (!compare_ether_addr(eth->h_dest, (mpc->mps_macs + i*ETH_ALEN))) if ( send_via_shortcut(skb, mpc) == 0 ) /* try shortcut */